Optical fibers are increasingly preferred over copper wires for the transmission of telecommunication signals and other data. Once used only in specialized, high-density applications, optical fiber networks are increasingly being used to provide signal transmission between service providers and users such as homes and businesses, for example. Optical fiber telecommunications systems often provide connections for telephone systems, video systems, computer networks, and other such systems.
Compared to conventional copper wiring, the physical routing of optical fibers, known as cable management is an area of significant concern in designing optical fiber equipment, due primarily to signal losses, fracturing, or breakage, which can occur when an optical fiber is bent too sharply. Each fiber has a minimum bend radius, which may not be exceeded without risking signal loss or other damage to the fiber. In addition, the fibers may be damaged if they are subjected to excessive tension or physical impact from external sources.
Optical fiber connection apparatuses, also known as outside plant distribution cabinets, distribution frames, or patch panels, are used wherever the interconnection or cross-connection of multiple optical fibers is required, such as where an optical fiber cable comprising numerous individual fibers enters a distribution cabinet, fiber frame, or patch panel for connection to the individual optical fibers that provide service to homes or businesses, for example. Due to space limitations, it is often desirable that such connection apparatuses allow for the interconnection of a large number of individual fibers in as small a space as possible, thus requiring a high density of connections. It is also desirable to make the work of technicians installing and servicing the connection apparatuses and associated optical fibers as simple as possible. Many patch panels are simply an open planar array of fiber optic adaptors, each of which allows the interconnection of two optical fibers by plugging specially tailored connectors into opposite ends of the adapter. The fibers can then be routed out of the panel thus allowing a large number of connectors to fit into a smaller patch panel without the routing and tracing of individual fibers becoming too difficult for the technician. It is, however, also necessary that the connection apparatus protect the fibers and connectors from damage due to excessive bending, excessive tension, or physical damage from the external environment.
A number of optical fiber cross-connect units are known in the prior art, which attempt to address the above-described problems through the use of protective shrouds or doors. Traditional central office fiber management uses a fixed bulkhead design and costly radius and physical fiber protection inside an overall housing. Examples of such prior art can be found in U.S. Pat. Nos. 7,266,280, 7,260,301, 6,915,059, 6,768,860, 5,778,130, 5,129,030, 4,708,430 and 4,630,886. While these apparatus provide some protection to the connectors and fibers, the fibers may then typically be routed only through the top and bottom of the unit or only through slots in the side of the unit. Density is therefore sacrificed to gain protection of the connectors and fibers.
As the prior art demonstrates, it has become problematic to address the multiple needs of an optical fiber interconnect device. For example, it is difficult to achieve high connection density, allow access to the front or rear of the connection panel, including both sides of the interconnecting adapter, for installation and maintenance activities, and protect the fibers and connectors from excessive bending, excessive tension, and mechanical damage from external sources. Moreover, it is challenging to provide an installer a range of options for cable routing from the front of the connection panel to facilitate the tracing of individual optical fibers and their removal or addition from the cable array. A need therefore exists, for an optical fiber management apparatuses that provide high connection density, easy access to the connection panel, protection to the fibers and connectors from excessive bending, stress, and external damage, while at the same time providing an installer a range of options for routing cables.